Shoutbox

please could someone help me?
i'm having a tabbed chat with a few conversations in, and each time i switch to another conversation, either through a keyboard shortcut or by clicking on the tab, the whole window gets a bit smaller through the bottom, and it does this every single time i try to switch tabs.
HELPPPPPPP!

are you using windowsblinds? if so its known to cause this problem, have a look at this thread for some solutions

thanks i get it now